With the unceasing development of display technology, curved display devices have become one of the research hotspots of the display technology field in recent years. Curved display devices have a certain radian, and can provide viewers with better visual experience, and reasons for this are as follows. On one hand, the human eyeball is protrusive to have a radian, and the distance from an eye to a screen can be assured of being equal by the radian of a curved display device. On the other hand, existence of the radian allows either end of the screen to be bent toward a viewer, so that a viewing angle at either end of the curved display device is substantially the same as that at the center.